IGN has penned up a list of gaming franchises/series that changed beyond recognition, which includes four franchises we have been covering for years: Fallout, Syndicate, X-COM, and Warcraft (in its World of Warcraft version). While IGN argues that the series managed to reinvent themselves, many of the ones they cite changed while passing in the hands of other developers or after a reboot meant to make them "more relevant". Here's a snip:

Syndicate

Bullfrog created a dark and violent corporate landscape in its 1993 PC strategy game Syndicate. The isometric tactical game stepped toward change with Syndicate Wars in 1996, but this year the series takes a completely different turn. With Starbreeze Studios taking over development duties, Syndicate is now a first-person shooter, picking and choosing which elements to bring into its modern iteration such as mini-guns (a classic power weapon), powerful corporations, and chip control. Put side to side it's difficult to discern that the two games have anything to do with each other, but they're certainly set in the same bleak future.

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XCOM

X-Com: UFO Defense is widely regarded as one of the best games of all time. And while Firaxis Games is recreating that classic game for a modern PC audience, 2K Games is also developing a first-person shooter based on a 1950s world and an alien invasion. XCOM the FPS was announced before the strategy remake, so fans cried foul at defiling such a sacred series. But with top-notch style and a focus on team-based combat, the new take on XCOM might turn fans into believers when it finally releases in 2013.

At least we're getting a turn-based true-to-form strategy title out of the X-COM reboot, coming from a big publisher and studio, and that's no small feat in recent times.